Machine for the stitching of buttonholes on garments

ABSTRACT

This disclosure relates in general to a machine for stitching buttonholes in the fabric of cut-out pieces of material, particularly outer garments such as jackets, coats, trousers, etc. The purpose of the invention is to automate as much as possible buttonhole stitching while protecting the garment being operated upon from damage which might arise from a defect in the associated control mechanisms.

United States Patent [191 Moll et al. Jan. 29, 1974 [54] MACHINE FOR THE STITCHING OF 3,228,364 1/1966 Kremer et al 1 12/121.1 1 BUTTONHOLES 0N GARMENTS 3,323,476 6/1967 Kass l l2/l2l.l l X I 3,599,583 8/1971 Berman et al. ll2/l2l.l2 [75] Inventors: Phlllpp Moll; Wolfgang Goebbels, 3,722,436 3/1973 Strouse 112/121.11

both of Aachen, Germany [73] Asslgnee: Xll,;?.%i;if 2;?;?," Primary q m q ,il i@i t lmw m"Wma V mama, Fi gent, 0r FirmDiller, Brown, Ramik & [22] Filed: Dec. 20, 1972 Wight [21] Appl. No.: 316,925

[57] ABSTRACT [30] Foreign Application Priority Data Dec. 22, 1971 Germany P 21 63 728.5 This disclosure relates in general to a machine for stitching buttonholes in the fabric of cut-out pieces of [52] US. Cl. ll2/l2l.12 material, particularly outer garments such as jackets, [51 Int. Cl D05b 21/00 coats, trousers, etc. The purpose of the inventionis to [58] Field of Search..... ll2/l2l.12, 121.]1, 121.15, automate as much as possible buttonhole stitching 112/ 121.29, 65, 203, 2 while protecting the garment being operated upon from damage which might arise from a defect in the [56] References Cited associated control mechanisms.

UNITED STATES PATENTS 3,151,583 10/1964 Troll et al. 112/121.1] 11 Claims, 3 Drawing Figures 10 i g H 1 x \r i 12 5 PAIENIED JAN 2 9197-? SHEET 2 OF 2 F m Lu iii $1 $2 53 FIG. 3

mil

MACHINE FOR THE STITCHING OF BUTTONHOLES ON GARMENTS The stitching of buttonholes adjacent a border or edge of an outer garment can be achieved only when the associated pieces.,of materials are in an assembled condition, i.e., the top, insertion, stiffening, lining, under-layer and similar materials are first stitched to gether and completed before the process of stitching the buttonholes therethrough is initiated. The buttonhole stitching process therefore must be carried out with the greatest care since the smallest of deviations from any precalculated position on the eventual garment is particularly obvious to a purchaser causing not only a complaint for a missewn buttonhole (or buttonholes) but more seriously an obvious reason for refusing to purchase the particular garment involved.

It is also important to recognize that from a commercial standpoint a mistake made in the stitching of a buttonhole cannot be repaired due to the cost involved and therefore the garment must be discarded or its cost reduced to the point where a loss is involved. Such loss represents considerable expense both from the standpoint of the material involved but more importantly because of overhead and labor costs.

Automatic stitching or sewing machines are well known in which a garment with a number of buttonholes placed at intervals to each other and parallel to each other, or in a line, each with the same distance from and uniformly relatively positioned from an edge of the garment can be stitched with ease and a degree of assurance of acceptability. Such conventional and special buttonhole stitching machines include a conventional needle carrying thread which is guided along and around the side of the buttonhole while the material is maintained firmly and stationarily in place. Essentially, the stitching head of the buttonhole stitching machine includes a carriage which is automatically controlled and can be moved longitudinally and transversely with respect to the direction of the buttonhole slit. ln machines of the foregoing type the material which is to be stitched is laid out upon a material carriage by the operator in accordance with predetermined indicia so that the front edge or the edge carrying the buttonhole slits lies parallel with and at a definite distance from the front edge of the material carrier. At the commencement of the stitching operation the buttonhole slit lying at the end of the buttonhole row is placed by the operator at a particular beginning stitching point after which the machine is energized and the first buttonhole will be stitched in the desired manner by preset control means with the stitching head being moved automatically in longitudinal and transverse directions relative to the buttonhole slit. Thereafter the material carrying carriage may be shifted manually to a next position whereat the next buttonhole to be stitched is again positioned relative to the stitching machine needle and the stitching process is again commenced with once again the stitching taking place at the same distance from the front edge of the material and/or relative to the material carrying carriage. Most common is the stitching of buttonholes in standard shirts in which the buttonhole slits are linearly arranged exact identical distances from each other and from the eges of the garment. In such cases little adjustment is necessary for proceeding from one buttonhole slitto another but mechanical switching devices are known in the art with variable settings in order that the button-- hole stitching machine can be adjusted to correspond the sewing to different buttonhole spacings, buttonhole lengths, etc. according to the stitching requirements desired.

The latter described buttonhole stitching machines cannot, unfortunately, be employed for stitching buttonholes in outer garment pieces becuase the latter do not have edges which run perfectly straight or rectilinear but instead are curved in one fashion or another. In such cases it is impossible to determine the position of a buttonhole slit by reference to the relative position of the garment or workpiece carrier but instead reference must be made to the actual position of the garment edge adjacent to the buttonhole in question which is to be stitched or sewn. The present invention is directed to eliminating the latter problem by taking advantage of the standard automatically driven material carriage which can be moved in two directions perpendicular to each other. More particularly, the invention deals with the technical task of adapting the relative position of the stitching needle or stitching head at the commencement of each individual buttonhole stitching operation to the actual and varying position of the material or garment edge rather than to a particular reference point of the material of garment carrying carriage.

The solution to the proposed problem is initially obtained from recognizing that at the time the material carrying carriage is set in its outgoing position for the initiation of the buttonhole stitching operation the load on the material carriage drive is independent of the nature of the garment thereon and therefore is to a large extent constant. It is therefore assumed that the run-out path of the material carrying carriage to its standstill position after power switch-off remains constant .because the varying loads occasioned by the nature of the garments carried thereby are relevant only at the time the buttonhole stitching operation is in progress but not in the setting of the garment carrying carriage to anyone of its stitching initiating positions.

In keeping with this invention the border edge of the garment to be sewn is probed by means of a photocelloptic system which includes a triple mirror and a photocell with the photocell providing the impulse for the stoppage of the garment carrying carriage as soon as the edge of the garment thereon has reached the desired stitching position of the stitching head or needle, and, after a short delay, provides an impulse for initiating the actual stitching operation. Since the material carrying carriage can stop in response to the impulse at a variety of relative positions to the stitching head of the stitching machine according to the position of the garment carried by the carriage, the provision of the light sensing mechanism just described cannot alone lead to a satisfactory solution of the technical problem and only the use of a switching technique which makes the impulse of the photocell effective only when the garment border edge is moved toward the desired stitching initiating position from a particular direction (from the front of the stitching head) will achieve the result desired.- The particular impulse switch-over or switching technique must be designed in such a way that it is possible to bring the machine into operation even if the garment border which is to be stitched has been brought beyond the desired initial stitching position. In such case the garment carrying carriage is first moved backward a distance corresponding to the photocell eclipsed or passed by its forward motion in order to be thereafter guided properly toward the initial stitching position. Thus the essential part of this invention is the provision of means by which the impulse from a photocell for stitching a particular buttonhole slit and switching on the buttonhole stitching head can only occur when the photocell is first exposed to and then blocked from a light-beam by a corresponding forward movement of the edge of the garment which is to be stitched.

One principal advantage of the latter-described lightbeam and photocell arrangement is that a satisfactory control of the machine can be achieved by but a single photocell.

A further. advantage of this invention is that should a defect in control occur as, for example, failure of the light source, a smudging or dirtying of the light source optics or the mirror associated therewith, the faulty operation of the switching mechanism is rendered impossible which frees the impulse for starting the stitching head only after the photocell has first been exposed and then eclipsed. Should this type of defect occur, therefore, damage to the garment which is to be stitched will be prevented.

In further keeping with this invention it is desired to permit the light-beam emanating from a light source to be operative independent of the thickness of the material or garment which is to be stitched and to do so the beam emanating from the light source is so arranged that the associated mirror of the triple optic system is mounted directly adjacent to the buttonhole which is to be stitched and the stitching plate of the sewing machine with the light-beam lying in a vertical plane passing through the plate of the stitching needle and parallel to the longitudinal direction of motion of the garment carrying carriage. Thus when the first buttonhole in a particular row is sewn the stoppage of the movement of the stitching machine and particularly the stitching needle releases the material carrying carriage for longitudinal movement toward the next buttonhole position in a manner known in the prior art after which by the system of this invention the succeeding buttonhole and those thereafter are stitched and finished off at a particular position.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the description, the appended clamed subject matter, and the several views illustrated in the accompanying drawings.

IN THE DRAWINGS FIG. 1 is a schematic view of a novel machine of this invention, and illustrates the relative arrangement of a stitching head and its associated needle, a photoelectricoptic system, and a garment carriage.

FIG. 2 is another schematic view of the machine of this invention and illustrates means for shifting the garment carriage with control mechanisms associated therewith.

FIG. 3 is a schematic view of a circuit constructed in accordance with the invention illustrating the components at their starting position with a photocell being eclipsed or the beam from a light source broken by the garment associated with the machine of FIGS. 1 and 2.

Reference is first made to FIG. 1 of the drawings which illustrates a buttonhole stitching machine 1 of an overall conventional construction which can be automatically programmed and/or operated in response to a control system which in turn is responsive to the position of an edge or border of a garment 7 which is to be sewn particularly in the area of buttonhole slits 8.

The machine 1 includes a conventional presser foot 5 which holds the garment 7 against an apertured stitching plate 3 in order that a conventional stitching needle (not shown) carrying thread (also not shown) reciprocated along the line 11 may form a caterpillar seam around the buttonhole openings 8.

The sewing machine 1 is preferably an eye or buttonhole stitching machine and as is conventional the garment carrying carriage 6 associated therewith includes clamps (not shown) for holding the garment 7 thereupon. As is apparent from FIGS. 1 and 2 the edge or border of the garment 7 which includes the buttonhole slits 8 projects beyond the edge of the carriage 6 into the area of the stitching needle and the stitching plate 3 with movement to the carriage 6 being provided in two normal directions, as is best indicated in FIG. 1 by the double headed arrows l3 and 14. The particular mechanical arrangment for automatically moving the carriage 6 in the direction of the double headed arrow 13 after the completion of the stitching of a buttonhole corresponds essentially to arrangements which are conventionally in existence in known buttonhole stitching machines and does not, therefore, form a part of this invention. As should be most apparent the movement in the direction of double headed arrow 13 corresponds simply to mechanism for motion which is perfectly linear having no concern for curved edges of the garment 7 and such is readily accomplished by conventional mechanisms as is controls therefor which would change the shifting depending upon the distance between the buttonholes 8.

In accordance with the present invention the problem which is solved is that of the particular motion imparted to the carriage 6 in the direction of the double headed arrow 14 which is in direct dependence upon the curvature of the border or edge of the garment 7 which is to be positioned such that the buttonhole slits 8 may be properly sewn. Motion is imparted to the carriage 6 in the direction of the double headed arrow 14 of FIG. 1 by a pair of hydraulic cylinders 17, 18 having respective rods 19, 20 connected to a support 21 which is in turn connected to the carriage 6. A control arm 22 is additionally carried by the support 21. A valve or similar control mechanism S1 is provided for controlling the motion imparted to the piston rod 19 in the direction of motion of the carriage 6 toward the sewing area which is to the right as viewed in FIG. 2 whereas a similar mechanism S2 is provided for controlling the input to the cylinder 18 for controlling the motion of the carriage 6 away from the sewing area 3 which as viewed in FIG. 2 is to the left. The mechanisms S1, S2 may be, for example, servo valves which control the input and exhaust ports to be cylinders 17, 18, respectively.

Control switches E86 and BS7 (FIG. 2) are shown schematically in association with the control arm 22 carried by the carriage 6 and are suitably mounted upon a frame (not shown) of the machine 1. These switches are normally open at the starting position of a sewing operation, as indicated in FIG. 3, with the switch ES6 being closed by the control arm 22 as the carriage 6 moves away from the starting position toward the stitching area or stitching plate 3 whereas in the reverse direction the switch ES7 will close.

At the stitching position a light-beam 15 emanating from a light source 9 is provided as is a photocell whereby in the triple system illustrated in FIGS. 1 and 2 a mirror or reflected surface 16 at the stitching area 3 reflects the light from the source 9 to the photocell 10. In order to assure that the photo-optical system is independent of the thickness of the garment 7 carried by the carriage 6 the light beam is directed such that it lies in a vertical plane which passes through the axis 1 1 of the stitching needle (not shown) reciprocally mounted in the stitching head 4 which is also a plane perpendicular to the garment or workpiece 7 and parallel to the direction indicated by the double headed arrow 13 of FIGS. 1 and 2.

Preferably though not necessarily an upper surface of the carriage 6 is flush with an upper surface of a plate 2 of the machine 1 which carries the stitching plate 3. This common plane between the plate 2, the plate 3 and the upper surface of the carriage 6 provides a uniform transition zone between the garment 7 and the machine 1 during movement of the carriage 6 as can be readily appreciated best from FIG. 2. Additionally carried by the plate 2 is a switch ES] (FIG. 3) whereas a line 12 (FIG. 1) represents a horizontal line through the stitching point parallel to the longitudinal motion of the carriage 6 as represented by the double headed arrow 13.

Reference is now made particularly to the circuitry of FIG. 3 which represents the components thereof at the beginning of the sewing operation at which point the garment or workpiece 7 lies upon the carriage 6 with its border projecting beyond the rightmost edge thereof as viewed in FIG. 2 and adjacent the sewing head 4, the manner best depicted in FIG. 1.

The buttonhole stitching operation is initiated by depressing a starting button T1 (FIG. 3) resulting in the energization of a start delay B having contacts bl-b3 which are normally open and b4 which is normally closed. At this point the light-beam is in operation as light is emanating from the source 9 and it is being reflected back to the photocell 10 with the latter being exposed resulting in the movement of the garment carriage 6 toward the stitching head 4 and the stitching area 3.

The edge or border or the garment 7 having the button-hole slits 8 eventually will break the beam 15 emanating from the photocell 9 at which time motion to the right as viewed in FIG. 2 of the carriage 6 will terminate and motion will be imparted to the needle to sew the first buttonhole. At this point it should be appreciated that each buttonhole is spaced a predetermined distance from the edge of the garment 7 and the position longitudinally established which is in the direction of the arrow 13 is conventional and hence is of no concern in regard to the present invention.

After the completion of the first stitching operation the carriage 6 will be shifted a predetermined distance in the direction of the double headed arrow 13 in the conventional manner by conventional apparatus heretofore mentioned and if during such movement the light-beam 15 is not broken the conventional switching operation is repeated to achieve stepping motion of the carriage 6 in the direction of the arrow 14 until such time as the beam 15 from the photocell 10 is eclipsed by the garment 7 which results in movement of the carriage 6 in the direction of the arrow 14 until the beam 15 is once again exposed. The latter motion is effected by the rod 20 (FIG. 2) and thus as described it will be appreciated that stitching or motion of the stitching needle (not shown) will be initiated only when the carriage 6 is moved by the piston rod 19 or in effect only when the carriage 6 is pushed thereby toward the sewing area 3 in responseto the control mechanism S1.

In order to more specifically understand the manner in which the machine operates in conjunction with the movement of the carriage 6 FIG. 3 has been provided with numerals 11-17 from left-to-right which indicate current paths and the same are incorporated in the following description in brackets after corresponding contact designations.

When the buttonhole stitching machine 1 is inoperative and the presser foot 5 is raised the End Operation Switch E8] is held in a closed position by the conventional lever (not shown) of the presser foot and so deactivates relay A [1]. Contact 01 [5] of relay A opens, contact a2 [7] closes and contact a3 [12] closes. The beam 15 from the photocell 9 is broken by the material or garment 7 and a relay H [8] of the photocell 10 is not activated.

If the push button T1 [2] is depressed the relay B[2] will be energized and will remain such by means of its now closed contact b1 [2]. At the same time contacts b2 [12] and b3 [13] are closed whereas contact b4 [15] opens. Relay L [13] is energized since contact gl [2] and contact b1 [2] remain closed as are contacts a3 [12], b 3[13], i3 [13] and k1 [13]. With relay L [12] being energized contact 1 2 [17] closes allowing the control mechanism S2 (FIGS. 2 and 3) which may be a conventional solenoid valve to operate with the carriage 6 controlled thereby being moved appropriately,

namely, to the left as viewed in FIG. 2 such that the workpiece moves beyond the beam 15 and permits the reflection thereof back to the photocell 10. As soon as the latter occurs the photocell relay H [8] operates to open the contact hl [3] whereas contacts b2 [9] and h3 [12] close.

Relay J [12] is now energized through closed contacts gl [2], b1 [2], e2 [10] and b2 [9] and remains in this position due to closed contact i2 [11]. In addition with the energization of the relay J the contact i3 [13] opens, resulting in the opening of relay L and the deenergization of the solenoid valve s2 bringing the carriage 6 to a standstill. Once relay L has deenergized relay I will again be energized via the contacts gl [2], b1[2], a3 [12], b2 [12] b3 [12] and l 1 [12]. Relay K now activates the solenoid valve s1 [16] by means of its contact k2 16] resulting in the actuation of the rod 19 with the result that the carriage 6 and the garment 7 thereupon moves to the right as viewed in F IG. 2 with the garment 7 again eclipsing or breaking the beam 15 emitted from the photocell 9. Accordingly relay H [8] thereby opens and contacts k2 [9] and b3 [12] are opened causing the opening of relay K and the solenoid valve s1 [16] associated therewith due to the opening of the contact k2 [l6] and thus the cessation of movement of the carriage 6. Due to the opening of the relay H the relay C is energized closing contact gl [2], b1 [2], hl [3], i1 [3], (relay I remaining energized), d1 [3],fl [3] andg2 [3]. With the closure of contact 01 [12] the relay C actuates the solenoid s3 [12] which activates the pressure foot and thereby opens the end sewing switch ES] [1]. The switch ESl remains open during the remainder of the stitching process along with the relay A with the contacts a1 a2 [7] and a3 [12] returning to their initial positions as shown in FIG. 3. The control of the carriage 6 is at this time terminated by the opening of contact a3 [12]. Relay D is energized via contacts gl [2], b1 [2] and a1 [5] and remains is this positions by means of a template control switch E83 [4] and its contact d2 [4]. With the opening of contact d1 [3] the relay C becomes deenergized. When energized the relay C will initiate the operation of the stitching machine.

After completion of the stitching operation the material presser foot is raised once again and thus the contact of switch E51 [1] is closed energizing relay A. Relay E now becomes energized via contacts gl [2], b1 [2], b5 [4] and a1 [5]. Relay F [6] energizes through the end switch E54 [6] and contact e1 [6] which induces or energizes a motor m2 [7] via contactsf2-4 [6] resulting in the movement of the carriage 6 in a longitudinal direction (double headed 13) to the next working point as determined by the distance between the buttonhole slits 8 of the terminal 7. Contact e2 [10] opens and allows relay J [10] to deenergize.

During the forward movement of the carriage 6 in the longitudinal direction, once again indicated by the double headed 13 in FIG. 1, the switch E53 [4] located on the carriage 6 (not shown) which to this point remains closed now reaches a depression in a pattern associated with the garment 7 which marks the new sewing point (next buttonhole slit 8) and opens allowing the relay D [4] to deenergize. The motor has a small constant lag in order that the switch E83 [4] is driven out of the depression of the pattern and immediately closes.

Upon the opening of the contact d2 [4] the relay E [5] deenergizes resulting in the opening of the contact e1 [6] and the deenergization of the relay F [6] which interrupts forward movement of the carriage 6 and the fabric or garment 7 thereupon.

During forward propulsion or motion of the carriage 6 border position is controlled by the relay contacts a3 [12], b2 [12] and b3 [13]. If the photocell beam 15 is interrupted by the material the same procedure will take place as that described prior to the energization of the stitching machine at the first buttonhole encountercd. However, if the beam 15 is not broken by the garment 7 the relay H [8] will immediately energize and allow relay K to energize via contacts a3 [12], b2 [12], h3 [12] and i 1 [12] which results in the operation of the soleniod valve s1 and the movement of the carriage 6 upon the closing of the contact k2 [16] in the direction toward the photocell 9. The machine drive is then switched on as described earlier with the energization of the relay C.

When the sewing operations on the garment 7 are completed and the carriage has reached the end of its longitudinal motion the end switch E84 [6] which limits this movement is contacted and relay G [7] is energized through contacts E84 [6], d3 [7], b7 [7] and a2 [7]. The relay G [7] with its contacts g3-5 [7] will initiate the motion of the carriage 6 in its longitudinal direction back to the starting point to the energization of the motor m2. As contact G1 [2] switches over the connection to relay B [2] becomes dead and relay B [2] deenergizes. Relay G [7] remains in position during the return trip of the carriage 6 by means of the contacts gl [2], BS5 [7] and a2 [7] until the carriage has reached the starting position and opens end switch ES 5 [7] which is closed during the latter described procedure. Relay G then deenergizes and the motor m2 is stopped.

During the return trip the carriage 6 travels to the starting position of the transverse movement (middle position) and is brought thereto by the solenoid valve S1 [16] or S2 [17] through the contact b4 [15], the contacts BS6 [14] or E57 [16] both of which are closed from time to time or the relays K or L.

Should the border control of the carriage 6 be driven against the end positions during transverse movement the switch ES2 will be opened and the automatic sequence of the machine will be interrupted immediately. The carriage 6 will then return to its middle position of transverse movement in exactly the same way as during the automatic return trip. Thereafter the workpiece or garment 7 must then be reinserted in order that its ma terial edge which is to be sewn lies in the desired range of the border control mechanism.

While preferred forms and arrangement of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the scope and spirit of this disclosure.

We claim:

1. In a buttonhole stitching machine, in combination: a carriage adapted to receive a workpiece in indexed position thereon such that an edge of the workpiece extends generally longitudinally of the carriage; buttonhole means for automatically stitching buttonholes on the workpiece; means for stopping said carriage in the longitudinal direction upon completion of a buttonhole stitching cycle so as to achieve selected spacing between successive buttonholes stitched on the work piece; means for moving said carriage in either direction along a path perpendicular to said longitudinal direction; photoelectric means for detecting said edge of the workpiece as said carriage is moved along said path, and control means associated with said photoelectric means for stopping said carriage in its movement along said path and for initiating a buttonhole stitching cycle only in response to detection of said edge while the carriage is moving in one particular direction along said path.

2. In a buttonhole stitching machine as defined in claim 1 wherein said photoelectric means is epxosed when a workpiece is withdrawn from said buttonhole means and is eclipsed when a workpiece is properly positioned with respect to said buttonhole means, and said control means includes manual means for enabling a buttonhole cycle, means for starting a buttonhole cycle only in response to successive exposure and eclipse of said photoelectric means after the cycle is enabled, and means for causing said carriage to withdraw a workpiece until said photoelectric means is exposed and then to present a workpiece in the event that said photoelectric means is eclipsed at the instant a cycle is enabled.

3. In a buttonhole stitching machine as defined in claim 1 wherein said control means includes two switching contacts arranged in series for actuating said buttonhole means, one of said contacts being normally open and being closed only in response to exposure of said photoelectric means, and the other of said switching contacts being normally closed and being opened only in response to eclipsing of said photoelectric means.

4. In a buttonhole stitching machine as defined in claim 1 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the workpiece.

5. In a buttonhole stitching machine as defined in claim 2 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the workpiece.

6. In a buttonhole stitching machine as defined in claim 3 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the workpiece.

7. In a buttonhole stitching machine as defined in claim I wherein said control means includes a first relay energized in response to exposure of said photoelectric means, a second relay energized in response to energization of said first relay, and a pair of switch contacts one actuated by each of said first and second relays, that switch contact actuated by said first relay being normally closed and that switch contact actuated by said second relay being normally open.

8. In a buttonhole stitching machine, in combination: a carriage adapted to receive a workpiece in indexed position thereon so that an edge of the workpiece projects laterally from the carriage and extends generally longitudinally of the carriage; buttonhole stitching means disposed to one side of said carriage and including a stitch-hole device; means for translating said carriage back and forth along a path transverse to the carriage respectively to withdraw a marginal edge of the workpiece from above said stitch-hole device and to present such marginal edge over the stitch-hole device; control means for enabling and initiating a buttonhole stitching cycle, said control means including a manually controlled switch for enabling a cycle, photoelectric means for detecting the presence and absence of said marginal edge in predetermined relation to said stitch-hole device, means for withdrawing said carriage in the detected presence of said marginal edge at the enabling of the cycle and for presenting said carriage when the absence is subsequently detected, means for presenting the carriage in the detected absence of said marginal edge at the enabling of the cycle, and means for stopping said carriage and energizing said stitching means to initiate said cycle only in response to detection of said marginal edge while said carriage is being presented.

9. In a buttonhole stitching machine as defined in claim 8 wherein said control means includes two switching contacts arranged in series for actuating said buttonhole means, one of said contacts being normally open and being closed only in response to exposure of said photoelectric means, and the other of said switching contacts being normally closed and being opened only in response to eclipsing of said photoelectric means.

10. In a buttonhole stitching machine as defined in claim 8 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stiching means, a plane positioned perpendicular to the surface of the workpiece.

11. In a buttonhole stitching machine as defined in claim 9 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the workpiece. 

1. In a buttonhole stitching machine, in combination: a carriage adApted to receive a workpiece in indexed position thereon such that an edge of the workpiece extends generally longitudinally of the carriage; buttonhole means for automatically stitching buttonholes on the workpiece; means for stopping said carriage in the longitudinal direction upon completion of a buttonhole stitching cycle so as to achieve selected spacing between successive buttonholes stitched on the workpiece; means for moving said carriage in either direction along a path perpendicular to said longitudinal direction; photoelectric means for detecting said edge of the workpiece as said carriage is moved along said path, and control means associated with said photoelectric means for stopping said carriage in its movement along said path and for initiating a buttonhole stitching cycle only in response to detection of said edge while the carriage is moving in one particular direction along said path.
 2. In a buttonhole stitching machine as defined in claim 1 wherein said photoelectric means is epxosed when a workpiece is withdrawn from said buttonhole means and is eclipsed when a workpiece is properly positioned with respect to said buttonhole means, and said control means includes manual means for enabling a buttonhole cycle, means for starting a buttonhole cycle only in response to successive exposure and eclipse of said photoelectric means after the cycle is enabled, and means for causing said carriage to withdraw a workpiece until said photoelectric means is exposed and then to present a workpiece in the event that said photoelectric means is eclipsed at the instant a cycle is enabled.
 3. In a buttonhole stitching machine as defined in claim 1 wherein said control means includes two switching contacts arranged in series for actuating said buttonhole means, one of said contacts being normally open and being closed only in response to exposure of said photoelectric means, and the other of said switching contacts being normally closed and being opened only in response to eclipsing of said photoelectric means.
 4. In a buttonhole stitching machine as defined in claim 1 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the work-piece.
 5. In a buttonhole stitching machine as defined in claim 2 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the work-piece.
 6. In a buttonhole stitching machine as defined in claim 3 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the workpiece.
 7. In a buttonhole stitching machine as defined in claim 1 wherein said control means includes a first relay energized in response to exposure of said photoelectric means, a second relay energized in response to energization of said first relay, and a pair of switch contacts one actuated by each of said first and second relays, that switch contact actuated by said first relay being normally closed and that switch contact actuated by said second relay being normally open.
 8. In a buttonhole stitching machine, in combination: a carriage adapted to receive a workpiece in indexed position thereon so that an edge of the workpiece projects laterally from the carriage and extends generally longitudinally of the carriage; buttonhole stitching means disposed to one side of said carriage and including a stitch-hole device; means for translating said carriage back and forth along a path transverse to the carriage respectively to withdraw a marginal edge of the workpiece from above said stitch-hole device and to present such marginal edge over the stitch-hole device; control means for enabling and initiating a buttonhole stitching cycle, said control means incluDing a manually controlled switch for enabling a cycle, photoelectric means for detecting the presence and absence of said marginal edge in predetermined relation to said stitch-hole device, means for withdrawing said carriage in the detected presence of said marginal edge at the enabling of the cycle and for presenting said carriage when the absence is subsequently detected, means for presenting the carriage in the detected absence of said marginal edge at the enabling of the cycle, and means for stopping said carriage and energizing said stitching means to initiate said cycle only in response to detection of said marginal edge while said carriage is being presented.
 9. In a buttonhole stitching machine as defined in claim 8 wherein said control means includes two switching contacts arranged in series for actuating said buttonhole means, one of said contacts being normally open and being closed only in response to exposure of said photoelectric means, and the other of said switching contacts being normally closed and being opened only in response to eclipsing of said photoelectric means.
 10. In a buttonhole stitching machine as defined in claim 8 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stiching means, a plane positioned perpendicular to the surface of the work-piece.
 11. In a buttonhole stitching machine as defined in claim 9 wherein said photoelectric means produces a light beam which defines, with the perpendicular determined by the stitch-hole of the stitching means, a plane positioned perpendicular to the surface of the work-piece. 